shader
shader: string = `uniform vec2 metaCircleCenters[META_CIRCLE_COUNT];uniform float metaCircleRadii[META_CIRCLE_COUNT];const float k = 32.0;float metaCircleMinDistance(vec2 target, out float colorIndex) {colorIndex = 5.0;float res = 0.0;for (int i = 0; i < META_CIRCLE_COUNT; i++) {float dist = distance(metaCircleCenters[i], target) - metaCircleRadii[i];res += exp2(-k * dist);}return -log2(res) / k;}`